Abstract: Compared with the orthogonal space-time block codes(OSTBC) cooperation scheme,the liner dispersion codes cooperation system improves the performance of the system under high rate conditions.Two kinds of amplify-and-forward cooperation schemes based on liner dispersion codes is proposed.The main difference between these two schemes is when the noise of the relays is added to the liner dispersion codes,pre-and post-coding.Firstly,these two schemes have the same BER performance are proved.Secondly,the characteristics of the two schemes are analyzed.Compared one scheme with the other,one has a lower complexity of the relays and cooperative protocol,but has a lower rate in the first phase of the cooperation.Finally,the obtained results are verified through Monte Carlo simulation.